Watersheds - Quick Notes

Watersheds

• All of the land that drains into a specific body of water (river, lake, bay, etc.)
• Boundaries determined by slope; ridges divide watersheds, causing different runoff directions
• Key factors: vegetation, soil composition, and slope influence drainage
• Vegetation: More vegetation → more infiltration and groundwater recharge
• Slope: Greater slope → faster runoff velocity and more soil erosion
• Soil permeability: determines how much runoff vs infiltration occurs
• Human impacts: Agriculture, clearcutting, urbanization, dams, mining affect water quality

Quick relationships

• Infiltration rate: $I \propto V$
• Groundwater recharge: $G \propto I$
• Runoff velocity: $v_{\text{runoff}} \propto s$
• Runoff magnitude: $R \propto \frac{1}{P}$
• Infiltration and permeability: $I \propto P$